Unique features in the ribosome binding site sequence of the gram-positive Staphylococcus aureus beta-lactamase gene.
The base sequence of the ribosome binding site region of the Gram-positive Staphylococcus aureus beta-lactamase gene has been determined. The leader peptide sequence of 24 amino acids which precedes the NH2 terminus of extracellular S. aureus beta-lactamase has also been established. This initiation site possesses two unique features not observed for most initiation sites recognized by Escherichia coli ribosomes. A novel initiation codon, UUG, initiates protein synthesis with methionine; and a very strong Shine-Dalgarno complementarity containing five G-C base pairs precedes the UUG initiation codon. The strong Shine-Dalgarno complementarity may explain the reduced translational dependence on initiation factor IF-3 function that has been observed for the beta-lactamase mRNA and other mRNAs from Gram-positive bacteria. We suggest that this extent of complementarity between the mRNA and this extent of complementarity between the mRNA and the ribosome may be a requirement for efficient initiation by Bacillus subtilis and other Gram-positive ribosomes, and may provide the basis for the observed inability of the Gram-positive systems to translate most of the mRNAs from Gram-negative bacteria.
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics; D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005796:Genes; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000235:genetics; D014158:Transcription, Genetic; D001618:beta-Lactamases / Q000235:genetics*
D012321:DNA-Directed RNA Polymerases; D001618:beta-Lactamases